#include <cassert>
#include <cstdio>
#include <cstring>
#include <errno.h>
#include <iostream>
#include <cstdlib>
#include <time.h>

#ifdef WIN32

#include <winsock2.h>
#include <stdlib.h>
#include <io.h>

#else

#include <arpa/inet.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netdb.h>
#include <string.h>
#include <unistd.h>

#endif

#include <string.h>

#include "udp.h"

using namespace std;

Socket openPort(unsigned short port, unsigned int interfaceIp, bool verbose) {
    Socket fd;

    fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
    if (fd == INVALID_SOCKET) {
        int err = getErrno();
        cerr << "Could not create a UDP socket:" << err << endl;
        return INVALID_SOCKET;
    }

    struct sockaddr_in addr;
    memset((char*) &(addr), 0, sizeof((addr)));
    addr.sin_family = AF_INET;
    addr.sin_addr.s_addr = htonl(INADDR_ANY);
    addr.sin_port = htons(port);

    if ((interfaceIp != 0) && (interfaceIp != 0x100007f)) {
        addr.sin_addr.s_addr = htonl(interfaceIp);
        if (verbose) {
            clog << "Binding to interface " << hex << "0x" << htonl(interfaceIp) << dec << endl;
        }
    }

    if (bind(fd, (struct sockaddr*) &addr, sizeof(addr)) != 0) {
        int e = getErrno();

        switch (e) {
            case 0: {
                cerr << "Could not bind socket" << endl;
                return INVALID_SOCKET;
            }
            case EADDRINUSE: {
                cerr << "Port " << port << " for receiving UDP is in use" << endl;
                return INVALID_SOCKET;
            }
                break;
            case EADDRNOTAVAIL: {
                if (verbose) {
                    cerr << "Cannot assign requested address" << endl;
                }
                return INVALID_SOCKET;
            }
                break;
            default: {
                cerr << "Could not bind UDP receive port" << "Error=" << e << " " << strerror(e) << endl;
                return INVALID_SOCKET;
            }
                break;
        }
    }
    if (verbose) {
        clog << "Opened port " << port << " with fd " << fd << endl;
    }

    assert( fd != INVALID_SOCKET);

    return fd;
}

bool getMessage(Socket fd, char* buf, int* len, unsigned int* srcIp, unsigned short* srcPort, bool verbose) {
    assert( fd != INVALID_SOCKET);

    int originalSize = *len;
    assert( originalSize > 0);

    struct sockaddr_in from;
    int fromLen = sizeof(from);

    *len = recvfrom(fd, buf, originalSize, 0, (struct sockaddr *) &from, (socklen_t*) &fromLen);

    if (*len == SOCKET_ERROR) {
        int err = getErrno();

        switch (err) {
            case ENOTSOCK:
                cerr << "Error fd not a socket" << endl;
                break;
            case ECONNRESET:
                cerr << "Error connection reset - host not reachable" << endl;
                break;

            default:
                cerr << "Socket Error=" << err << endl;
        }

        return false;
    }

    if (*len < 0) {
        clog << "socket closed? negative len" << endl;
        return false;
    }

    if (*len == 0) {
        clog << "socket closed? zero len" << endl;
        return false;
    }

    *srcPort = ntohs(from.sin_port);
    *srcIp = ntohl(from.sin_addr.s_addr);

    if ((*len) + 1 >= originalSize) {
        if (verbose) {
            clog << "Received a message that was too large" << endl;
        }
        return false;
    }
    buf[*len] = 0;

    return true;
}

bool sendMessage(Socket fd, char* buf, int l, unsigned int dstIp, unsigned short dstPort, bool verbose) {
    assert( fd != INVALID_SOCKET);

    int s;
    if (dstPort == 0) {
        // sending on a connected port
        assert( dstIp == 0);

        s = send(fd, buf, l, 0);
    } else {
        assert( dstIp != 0);
        assert( dstPort != 0);

        struct sockaddr_in to;
        int toLen = sizeof(to);
        memset(&to, 0, toLen);

        to.sin_family = AF_INET;
        to.sin_port = htons(dstPort);
        to.sin_addr.s_addr = htonl(dstIp);

        s = sendto(fd, buf, l, 0, (sockaddr*) &to, toLen);
    }

    if (s == SOCKET_ERROR) {
        int e = getErrno();
        switch (e) {
            case ECONNREFUSED:
            case EHOSTDOWN:
            case EHOSTUNREACH: {
                // quietly ignore this
            }
                break;
            case EAFNOSUPPORT: {
                cerr << "err EAFNOSUPPORT in send" << endl;
            }
                break;
            default: {
                cerr << "err " << e << " " << strerror(e) << " in send" << endl;
            }
        }
        return false;
    }

    if (s == 0) {
        cerr << "no data sent in send" << endl;
        return false;
    }

    if (s != l) {
        if (verbose) {
            cerr << "only " << s << " out of " << l << " bytes sent" << endl;
        }
        return false;
    }

    return true;
}

void initNetwork() {
#ifdef WIN32
    WORD wVersionRequested = MAKEWORD( 2, 2 );
    WSADATA wsaData;
    int err;

    err = WSAStartup( wVersionRequested, &wsaData );
    if ( err != 0 )
    {
        // could not find a usable WinSock DLL
        cerr << "Could not load winsock" << endl;
        assert(0);// is this is failing, try a different version that 2.2, 1.0 or later will likely work
        exit(1);
    }

    /* Confirm that the WinSock DLL supports 2.2.*/
    /* Note that if the DLL supports versions greater    */
    /* than 2.2 in addition to 2.2, it will still return */
    /* 2.2 in wVersion since that is the version we      */
    /* requested.                                        */

    if ( LOBYTE( wsaData.wVersion ) != 2 ||
            HIBYTE( wsaData.wVersion ) != 2 )
    {
        /* Tell the user that we could not find a usable */
        /* WinSock DLL.                                  */
        WSACleanup( );
        cerr << "Bad winsock verion" << endl;
        assert(0);  // is this is failing, try a different version that 2.2, 1.0 or later will likely work
        exit(1);
    }
#endif
}

/* ====================================================================
 * The Vovida Software License, Version 1.0 
 * 
 * Copyright (c) 2000 Vovida Networks, Inc.  All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 
 * 3. The names "VOCAL", "Vovida Open Communication Application Library",
 *    and "Vovida Open Communication Application Library (VOCAL)" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact vocal@vovida.org.
 *
 * 4. Products derived from this software may not be called "VOCAL", nor
 *    may "VOCAL" appear in their name, without prior written
 *    permission of Vovida Networks, Inc.
 * 
 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, TITLE AND
 * NON-INFRINGEMENT ARE DISCLAIMED.  IN NO EVENT SHALL VOVIDA
 * NETWORKS, INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT DAMAGES
 * IN EXCESS OF $1,000, NOR FOR ANY INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
 * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 * 
 * ====================================================================
 * 
 * This software consists of voluntary contributions made by Vovida
 * Networks, Inc. and many individuals on behalf of Vovida Networks,
 * Inc.  For more information on Vovida Networks, Inc., please see
 * <http://www.vovida.org/>.
 *
 */

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